Magnetic beltscraper



Jan. 9, 1968 M. FEHR I 3,362,525

MAGNETIC BELTSCRAPER Filed April 25, 196 5 5 Sheets-Sheet 2 5. .49 v V INVENTOR.

Mex FEHE Jan. 9, 1968 M. FEHR MAGNETIC BELTSCRAPER Filed April 25, 1965 5 Sheets-Sheet 5 QTTOENEVS United States Patent 3,362,525 MAGNETIC BELTSCRAPER Max Fehr, Liberia Mining Company, Ltd., R0. Box 252, Monrovia, Liberia Filed Apr. 23, 1965, Ser. No. 450,364 7 (Claims. (Cl. 19823t)) This invention pertains to methods and apparatus for magnetically cleaning conveyor belts employed for transporting magnetic or partly magnetic, loose aggregate materials, such for example as iron ores, iron concentrates and the like.

It is essential to install with all conveyor belt systems, apparatus for cleaning the returning or lower belt strand. Such apparatus almost invariably employs one or a series of scraper bars, blades, wires or the like, which continuously wear the belt by abrasion and thus ultimately destroy the same.

I have discovered, however, in accordance with the present invention, that where the materials to be transported are magnetic or partly magnetic, that such scraper bars and the like may be dispensed with, and the return strand of the conveyor belt cleaned by magnetic withdrawal of the adhering particles of the material and by means of magnets spaced from the belt.

Although it has previously been known to employ in magnetic separators, and for separating magnetic from non-magnetic particles of loose aggregate mixtures thereof, belt conveyors having magnet means associated therewith for withdrawing and thereby separating the magnetic from the non-magnetic particles from such admixture disposed on the upper strand of a conveyor belt, or alternatively for adhering the magnetic particles to the return strand of the belt for thereby removing the n0nmagnetic particles by gravity, it has not to my knowledge been heretofore known, to employ magnets so disposed with reference to the return strand of a belt conveyor as to remove magnetic particles adhering thereto and for purposes of cleaning the same in accordance with the construction, mode of operation and function of the present invention as hereinafter described.

My invention is best explained in its various modifications by immediate reference to the accompanying drawings wherein:

FIG. 1 is a diagrammatic View in side elevation of a portion of a belt conveyor embodying preferred forms of the invention.

FIG. 2 is a plan view of a portion of the conveyor belt return strand as viewed from above, showing various dispositions of magnets with reference to the belt for cleaning the same according to the invention.

FIG. 3 is an enlarged sectional elevation as taken substantially at 3-3 of FIG. 2, to illustrate the relative disposition of the magnets with reference to the underside of the conveyor belt return strand, and further to illustrate the manner in which the belt cleaning action is accomplished thereby.

FIGS. 4a and 4b are views similar to FIG. 3, illustrative of various magnet shapes and mounting constructions which may be employed.

FIG. 5 is a view generally similar to FIG. 4, but illustrative of the manner in which the magnetic cleaning action may be implemented with spray jets of gaseous or liquid cleaning agents.

FIGS. 6a and 6b are, respectively, views in section and side elevation of one of the magnet assemblies, illustrating further details in mounting and assembling the same on a supporting structure.

Referring to FIG. 1, shown therein is a portion of an endless conveyor belt 10, travelling about an end pulley 11, and thence on the return strand 10a of the belt,

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tautly over a bend pulley 12. A series of permanent magnet assemblies are mounted, as at 14, directly beneath the end pulley 12, or alternatively, as at 15, between the end and bend pulleys 11, 12, or if found desirable or expedient at both such positions, for purposes of cleaning the underside of the returning belt strand 10a in the manner explained below.

In order to achieve a thorough cleaning of the belt, these magnet assemblies must span the entire width of the belt in the manner illustrated in FIG. 2, and to this end may extend in one or more linear rows across the entire width of the belt, as at 16 or 17, or may be disposed in staggered or V formation, as at 18 or 19, or in other possible ways. But whatever arrangement is employed, it must be such as to expose the entire width of the belt to the magnetic cleaning action. The cleaning action is of course enhanced by employing a plurality of rows of such magnets, as illustrated for example at 17, FIG. 2.

The construction of each magnet assembly and its mounting with reference to the return strand of the conveyor belt is best illustrated in FIG. 3. In the embodiment shown, each magnet assembly comprises a U magnet, as at 20, having cast thereabout, a support 21, of rubber or other non-magnetic, resilient plastic. The invention is characterized by the fact that the magnet 20 does not touch the conveyor belt return strand 10a, but is spaced therefrom, as indicated at 22.

Thus when the conveyor belt loaded with adhering magnetic particles, as at 23, travels across and over the magnet 20, the particles 23 will be pulled by the magnetic attraction onto the magnet until the available space between the belt and magnet is filled with this material, as at 24. On the approach side of the belt traverse, this particulate material will accumulate, as at 25, in area A and fall away in part under gravity action, being partially rubbed off by the belt in this area. The remainder will be fed along through area B between the belt and magnet by the magnetic attraction thereof and thus be fed into area C where it falls away under gravity action, as at 26.

It is essential in accordance with the invention that the maximum possible magnetic force be directed to that area of the belt which is to be cleaned. Single magnets of sumcient width to span the conveyor belt may be employed or a series of such magnets may be employed with their like poles in alignment, respectively. U- shaped magnets may thus be employed as at 20, FIGS. 3 and 4a, or rod-shaped magnets having soft iron pole pieces may be employed, as at 27, 28, FIG. 4b. These magnet or magnet assemblies, are cast in rubber or other resilient supports, as at 29, 30, FIGS. 4a, 4b, and in such manner that only the pole faces are exposed to the conveyor belt, as at 31, 32.

The mounting of the magnets is characterized in that r they are resiliently mounted in rubber or equivalent, as

above noted, and also in such manner that they can be removed in a direction parallel to the conveyor belt. To this end the mountings include resilient supporting strips, as at 33, which may be reinforced with wire mesh embedded therein, as at 34. At their lower ends the supporting strips 33, are secured against a support beam 35, by means of outer metal strips 36, 37, and bolts, as at 38, having nuts, as at 39, threaded thereon for tightening and removal.

In the event that extremely dirty conveyor belts require additional cleaning with fluid cleaning agents, gaseous or liquid, this may be accomplished in the manner shown in FIG. 5, by injection of the fluid under pressure through passages provided, as at 40, 41, in the cast rubber or equivalent blocks, as at 42, in which the magnets are mounted, as at 20. In this way the cleaning agent will be injected and distributed throughout the magnetic material collected and concentrated as in the area B, FIG. 3. Thus theentire volume of the magnetic material will be soaked with the cleaner as well as the entire surface of the conveyor belt to be cleaned. If a liquid cleaning agent is employed dust formation will be minimized, and if a 5 gaseous cleaning agent is employed, drying the conveyor belt is achieved.

Referring to FIGS. 6a and 6b, in order to prevent the spaces between the supporting strips 33, being filled with dust, these spaces may be filled with foam rubber or the like, as at 43.

Although the invention has been described with reference to the employment of permanent magnets for cleaning the conveyor belt, it will be understood that electromagnets may be employed instead.

What is claimed is:

1. Apparatus for magnetically cleaning conveyor belts and the like, comprising: a pulley, a conveyor belt passing thereabout, magnetic means disposed at a fixed position beneath said pulley in spaced relation to said belt and spanning the width thereof for removing magnetic particles adhering to said belt as said belt travels between said pulley and said magnetic means, said magnetic means including means for spraying a cleaning agent against said particles and belt to assist in said cleaning action.

2. Apparatus for magnetically cleaning conveyor belts and the like, comprising in combination: an end pulley for a travelling belt, a bend pulley for said belt mounted adjacent said end pulley, an endless belt passing about said end pulley and over said bend pulley, magnetic means mounted adjacent said belt but in spaced relation thereto between said end and bend pulleys, said magnetic means spanning the width of said belt for removing magnetic particles adhering thereto, and said magnetic means including means for spraying a cleaning agent against said particles and belt to assist in said cleaning action.

3. Apparatus according to claim 2, wherein said magnet means comprises a series of resiliently mounted permanent magnets having elongated pole faces successively disposed across the width of the belt.

4. Apparatus according to claim 2, wherein said magnet means comprises a series of permanent U-shaped magnets having elongated pole faces successively disposed with like pole faces in alignment across the entire Width of said belt, and wherein said magnets are mounted in resilient supports of non-magnetic, elastomeric material, and wherein said supports are detachably secured to a rigid mounting member.

5. Apparatus according to claim 2, wherein said belt and pulley are made of non-magnetic material.

6. Apparatus for magnetically cleaning conveyor belts and the like, comprising: rotatably mounted end and bend pulleys spaced slightly apart, an endless conveyor belt and means including said pulleys for continually moving said belt over and about said end pulley and the return strand thereof thence tautly over said bend pulley, a series of permanent magnets disposed in fixed position to span the entire width of said belt in the area thereof extending from a point beneath said end pulley to a point adjacent said bend pulley, each said magnet having elongated pole faces and being cast in a block of non-magnetic, elastomeric material with said pole faces disposed below and in spaced relation to said return strand of said belt, said elastorneric blocks having integral therewith supporting strips of said material for mounting the same on a rigid support, and means detachably mounting said strips on said rigid support, thereby resiliently to mount said magnet.

7. Apparatus according to claim 6 wherein said magnets are of a substantially U-shaped configuration and are mounted with their like poles substantially in alignment.

References Cited UNITED STATES PATENTS 758,655 5/1904 Irnlay 2l41 2,482,882 9/1949 Swanson.

2,911,330 11/1959 Clark l51.5 X 3,267,840 8/1966 Honma et a1. 1.7

FOREIGN PATENTS 768,860 2/1957 Great Britain.

EVON C. BLUNK, Primary Examiner.

R. I. HICKEY, Assistant Examiner. 

1. APPARATUS FOR MAGNETICALLY CLEANING CONVEYOR BELTS AND THE LIKE, COMPRISING: A PULLEY, A CONVEYOR BELT PASSING THEREABOUT, MAGNETIC MEANS DISPOSED AT A FIXED POSITION BENEATH SAID PULLEY IN SPACED RELATION TO SAID BELT AND SPANNING THE WIDTH THEREOF FOR REMOVING MAGNETIC PARTICLES ADHERING TO SAID BELT AS SAID BELT TRAVELS BETWEEN SAID PULLEY AND SAID MAGNETIC MEANS, SAID MAGNETIC MEANS INCLUDING MEANS FOR SPRAYING A CLEANING AGENT AGAINST SAID PARTICLES AND BELT TO ASSIST IN SAID CLEANING ACTION.
 6. APPARATUS FOR MAGNETICALLY CLEANING CONVEYOR BELTS AND THE LIKE, COMPRISING: ROTATABLY MOUNTED END AND BEND PULLEYS SPACED SLIGHTLY APART, AN ENDLESS CONVEYOR BELT AND MEANS INCLUDING SAID PULLEYS FOR CONTINUALLY MOVING SAID BELT OVER AND ABOUT SAID END PULLEY AND THE RETURN STRAND THEREOF THENCE TAUTLY OVER SAID BEND PULLEY, A SERIES OF PERMANENT MAGNETS DISPOSED IN FIXED POSITION TO SPAN THE ENTIRE WIDTH OF SAID BELT IN THE AREA THEREOF EXTENDING FROM A POINT BENEATH SAID END PULLEY TO A POINT ADJACENT SAID BEND PULLEY, EACH SAID MAGNET HAVING ELONGATED POLE FACES AND BEING CAST IN A BLOCK OF NON-MAGNETIC, ELASTOMERIC MATERIAL WITH SAID POLE FACES DISPOSED BELOW AND IN SPACED RELATION TO SAID RETURN STRAND OF SAID BELT, SAID ELASTOMERIC BLOCKS HAVING INTEGRAL THEREWITH SUPPORTING STRIPS OF SAID MATERIAL FOR MOUNTING THE SAME ON A RIGID SUPPORT, AND MEANS DETACHABLY MOUNTING SAID STRIPS ON SAID RIGID SUPPORT, THEREBY RESILIENTLY TO MOUNT SAID MAGNET. 